抄録
Microscopic sintering behavior in compacts formed by pressing ceramic granules is examined to develop a constitutive model for macroscopic sintering deformation analysis. Spray-dried alumina granules are compacted by CIPing and the compacts are fired at various temperatures. The internal structure composed of fractured and unfractured granules, and large crack-like cavities caused by their inhomogeneous shrinkage during sintering are observed. The macroscopic sintering rate becomes slow because of the formation of the large cavities. A basic constitutive equation for sintering of ceramic powder compacts is proposed with the grain boundary diffusion and grain growth taken into account. The relationship between the change in the microstructure and the shrinkage rate of the powder compacts is modelled by using the basic constitutive equation. The constitutive model is applied to the finite element analysis to predict the shape change of sintering bodies. The calculated results show good agreement with the experimental results.
